Power saving display mode for organic electroluminescent displays

ABSTRACT

An improved organic electroluminescent display includes a plurality of normal mode colors and a plurality of user-selected power saving mode colors. The display is switchable between a normal display mode and a power saving display mode. In the normal display mode, the normal mode colors are displayed by the display. Conversely, in the power saving display mode, the power saving mode colors are displayed by the display.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of copending U.S. application Ser.No. 10/723,803, now U.S. Pat. No. ______, filed on Nov. 25, 2003,incorporated herein by reference in its entirety.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable

INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC

Not Applicable

NOTICE OF MATERIAL SUBJECT TO COPYRIGHT PROTECTION

A portion of the material in this patent document is subject tocopyright protection under the copyright laws of the United States andof other countries. The owner of the copyright rights has no objectionto the facsimile reproduction by anyone of the patent document or thepatent disclosure, as it appears in the United States Patent andTrademark Office publicly available file or records, but otherwisereserves all copyright rights whatsoever. The copyright owner does nothereby waive any of its rights to have this patent document maintainedin secrecy, including without limitation its rights pursuant to 37C.F.R. § 1.14.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention pertains generally to organic electroluminescentdisplays, and more particularly to methods for conserving power consumedby organic electroluminescent displays.

2. Description of Related Art

Liquid crystal displays (LCDs) are widely used for portable computersand other products. One major disadvantage of an LCD is that an LCDemits no light; only the transparency of an LCD changes by adding or notadding a voltage. To obtain a high contrast, an LCD requires abacklight. Unfortunately, a backlight lamp consumes much power, e.g.,more than one-half of the total power that a laptop personal computer(PC) consumes. The power consumption of the LCDs is an important matterfor battery operated portable products.

Current state-of-the art displays include organic electroluminescent(OEL) displays. OEL displays are slowly being introduced into theelectronics market. Unlike LCDs, each pixel on an OEL display emitslight. Therefore, a backlight is not required. Further, OEL displays canbe slimmer than LCDs. It is likely that in many applications LCDs willbe replaced with OEL displays in the near future.

As stated above, OEL displays emit light. It happens that darker colorsconsume less power than brighter colors. As such, darker colors arepreferable for power saving. However, white, or other brighter colors,are commonly used as background colors for windows in a PC, and thesecolors increase the power consumption of OEL displays. Accordingly, ifbrighter colors occupy most areas of the display screen, a color reversemight be good in order conserve power consumption. Microsoft Windows OS,for example, has such a color reverse feature. A user can change thedisplay mode in a display appearance window. Unfortunately, this featurecan only be applied to Windows graphic objects; that is, windowbackground, frames, menus, etc. Many web pages use white as a backgroundcolor, but this background color remains the same regardless of userWindows settings. Therefore, the Windows color reverse feature is notbeneficial for power conservation. In order to maximize powerconservation, all brighter colors on the display screen should bechanged to darker ones.

The present invention recognizes the present drawbacks and provides asolution to one or more of the problems associated therewith.

BRIEF SUMMARY OF THE INVENTION

An aspect of the invention is to provide a self-emitting display such asan organic electroluminescent display that includes a plurality ofnormal mode colors and a plurality of power saving mode colors. Eachpower saving mode color is assigned to a normal mode color. During apower saving display mode, each normal mode color having an assignedpower saving mode color is switched to the assigned power saving modecolor.

In a preferred embodiment, each normal mode color not having an assignedpower saving mode color is reversed during a power saving display mode.Moreover, a user can assign each power saving mode color to a normalmode color. Preferably, the display includes a power saving indicatorthat shows the reduction in energy consumed by the display when it is inthe power saving display mode. The power saving display mode can beentered manually or automatically. In a preferred embodiment, thedisplay is an organic electroluminescent display.

Another aspect of the invention is a method for conserving power in anorganic electroluminescent display. The method includes providing aplurality of normal mode colors and providing a plurality of powersaving mode colors. Each power saving mode color is assigned to a normalmode color. In a power saving display mode, each normal mode colorhaving an assigned power saving mode color is switched to the assignedpower saving mode color.

A still further aspect of the invention is an organic electroluminescentdisplay having a plurality of plural normal mode colors and a pluralityof power saving mode colors. In this aspect of the present invention,the display is switchable between a normal display mode, in which thenormal mode colors are displayed, and a power saving display mode, inwhich the power saving mode colors are displayed.

Further aspects of the invention will be brought out in the followingportions of the specification, wherein the detailed description is forthe purpose of fully disclosing preferred embodiments of the inventionwithout placing limitations thereon.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)

The invention will be more fully understood by reference to thefollowing drawings which are for illustrative purposes only:

FIG. 1 is a block diagram of an organic electroluminescent displaysystem.

FIG. 2 is a flow chart of the configuration logic according to thepresent invention.

FIG. 3 is a view of a color configuration window according to thepresent invention.

FIG. 4 is a color selection window according to the present invention.

FIG. 5 is a flow chart of the operating logic according to the presentinvention.

DETAILED DESCRIPTION OF THE INVENTION

Referring more specifically to the drawings, for illustrative purposesthe present invention is embodied in the apparatus generally shown inFIG. 1 through FIG. 5. It will be appreciated that the apparatus mayvary as to configuration and as to details of the parts, and that themethod may vary as to the specific steps and sequence, without departingfrom the basic concepts as disclosed herein.

Referring initially to FIG. 1, an organic electroluminescent displaysystem is shown and is generally designated 10. As shown, the system 10includes a display 12, such as an organic electroluminescent (OEL)display, to which a power supply 14 is connected. It can be appreciatedthat the power supply 14 can be an alternating current (AC) power supplyor a direct current (DC) power supply. Moreover, a processor 16 isconnected to the display 12. The processor 16 includes a program,described below, that can be used to conserve the power consumed by thedisplay 12 during operation. FIG. 1 further shows a user interface 18that is connected to the processor 16. The user interface 18 can be, forexample, a keyboard, a mouse, an electric pen, etc. In lieu of a userinterface 18, the display 12 can include touch screen functionality thatcan act as a user interface. FIG. 1 further shows that the system 10further includes a power saving indicator 20 that can appear on thedisplay 12 in order to show the reduction in energy consumption of thedisplay 12 when it is in the power saving display mode, described indetail below.

It is to be understood that the processor 16 includes a program thatprovides a power saving display mode for the display 12. The program,described below, increases the energy efficiency of the display 12 whilemaintaining the clarity of the display. In other words, the easiest wayto convert bright colors to dark colors is to automatically reverse thecolors. However, this results in a bizarre display scheme, i.e., itlooks like a photo negative, that is difficult to see. Additionally, thebackground color can be user selected and it may be darker in normalmode. Thus, when reversed, the background color is going to be brighter.The program according to the present invention allows a user to freelyassign a power saving display mode color to each normal mode color andwhen the power saving display mode is executed each normal mode color ischanged to its corresponding power saving display mode color.

Referring now to FIG. 2, configuration logic according to the presentinvention is shown and commences at block 50 with a do loop, whereinwhen a button, e.g., a color configuration button, is toggled, thefollowing steps are performed. At block 52, a color configuration windowis displayed. Thereafter, at block 54, a menu of normal mode colors isprovided, e.g., within the color configuration window. Moving to block56, a menu of power saving mode colors is also provided, e.g., withinthe color configuration window. Proceeding to block 58, a user isallowed to select one or more normal mode colors for each elementdisplayed on the display 12 (FIG. 1). At block 60, a user is allowed toselect a power saving mode color for each normal mode color. The logicthen ends at state 62.

FIG. 3 shows a non-limiting, exemplary embodiment of a colorconfiguration window, generally designated 100. As shown, the colorconfiguration window 100 includes a normal mode column 102 that includesa first color indication square 104, a second color indication square106, a third color indication square 108, and a fourth color indicationsquare 110. The color configuration window 112 also includes a powersaving mode column 112 that includes a first color indication square114, a second color indication square 116, a third color indicationsquare 118, and a fourth color indication square 120.

It is to be understood that in a non-limiting, exemplary embodiment,user can select a normal mode color for a particular element displayedon the display 12 (FIG. 1) by using the user interface 18, e.g., amouse, to move a cursor to a particular color area or color element onthe display 12. Then, the user can drag-and-drop that particular colorarea or color element into a color indication square 104, 106, 108, 110in the normal mode column 102, e.g., the first color indication square104. After that, the user can toggle or otherwise click on thecorresponding first color indication square 114 in the power saving modecolumn 112 to open a color selection window, e.g., the color selectionwindow shown described below in conjunction with FIG. 4. Using the colorselection window, the user can select a power saving mode color for thecorresponding normal mode color shown in the first color indicationsquare 104. Similarly, the user can drag-and-drop other colors into thesecond and third color indication squares 106, 108 in the normal modecolumn 102 and choose corresponding power saving mode colors for eachnormal mode color via the color selection window.

It can be appreciated that more than four color indication squares 104,106, 108, 110 can be included in the normal mode column 102 and as such,the power saving mode column 112 can include more than four colorindication squares 114, 116, 118, 120. Moreover, it can be appreciatedthat the color configuration window 100 can include names of particulargraphic objects, e.g., desktop, scrollbar, background, etc., adjacent tocorresponding color indication squares 104, 106, 108, 110 in the normalmode column 102. In such an embodiment, a user does not have todrag-and-drop each object color—he or she can simply select a normalmode color and a power saving mode color for each graphic object listedin the color configuration window 100.

Further, it is to be understood that the fourth color indication square110 in the normal mode column 102 and the corresponding fourth colorindication square 120 in the power saving mode column 112 can be a“catch-all” configuration setting for all other remaining colors notgiven a corresponding power saving mode color. For example, by selectingan original colors square 122 all other normal mode colors not assigneda power saving mode color can remain their original color during thepower saving mode. On the other hand, if a reversed colors square 124 isselected, the other colors not assigned a power saving mode color can bereversed during the power saving mode.

FIG. 4 shows a color selection window, generally designated 150. Asshown in FIG. 4, the color selection window 150 includes a basic colorsmenu 152 and a custom colors menu 154 from which a user can select powersaving mode colors as described above.

Referring to FIG. 5, a non-limiting, exemplary embodiment of theoperating logic according to the present invention is shown andcommences at block 200 with a do loop, wherein during operation, thesucceeding steps are performed. At block 202, the normal mode colors aredisplayed at the display 12 (FIG. 1). Next, at decision diamond 204, itis determined whether a power saving display mode is selected. The powersaving display mode can be selected manually by a user. Alternatively,the power saving display mode can be selected automatically, e.g., whenthe power supply 14 (FIG. 1) is switched from AC to DC or if the powerlevel within the power supply 14 (FIG. 1) has fallen below a minimumpower threshold.

If the power saving mode is not selected, the logic returns to block 202and the normal mode colors continue to be displayed by the display 12.Otherwise, if the power saving mode is selected the logic proceeds toblock 206 and the power saving mode colors previously selected by a userare displayed. Additionally, the normal mode colors that are notassigned power saving mode colors, are simply reversed or remain theiroriginal colors. Thereafter, moving to decision diamond 208, it isdetermined whether a normal display mode has been selected, e.g.,threshold or manually. If so, the logic returns to block 202 and thenormal mode colors are again displayed. The logic then continues asdescribed above. If the normal display mode is not selected, the logicreturns to block 206 and the power saving mode colors continue to bedisplayed.

It is to be understood that a graphic memory within the processorusually stores three (Red, Green, Blue) 8-bit data per pixel. The screenon the display 12 is drawn based on the graphics data within the graphicmemory. With the system and method described above, a user can select apower saving mode color for one or more normal mode colors. Duringoperation, when a power saving mode is entered, the normal mode colorsare switched to their corresponding power saving mode colors.Specifically, each of the pixel data is replaced with a new value basedon the color conversion information that a user inputs in the colorconfiguration window 100 (FIG. 3).

Thereafter, when the normal mode is entered, the power saving modecolors revert back to the normal mode colors. Accordingly, a user caneffectively choose which normal mode colors are to be switched duringpower saving mode in order to effectively conserve power whilemaintaining screen clarity on the display 12 (FIG. 1). It can beappreciated that the power saving display mode can be used inconjunction with displays other than OEL displays. Moreover, the display12 (FIG. 1) can be used in conjunction with a computer, a cellulartelephone, a personal data assistant (PDA), or any otherenergy-sensitive device that includes a display.

Although the description above contains many details, these should notbe construed as limiting the scope of the invention but as merelyproviding illustrations of some of the presently preferred embodimentsof this invention. Therefore, it will be appreciated that the scope ofthe present invention fully encompasses other embodiments which maybecome obvious to those skilled in the art, and that the scope of thepresent invention is accordingly to be limited by nothing other than theappended claims, in which reference to an element in the singular is notintended to mean “one and only one” unless explicitly so stated, butrather “one or more.” All structural, chemical, and functionalequivalents to the elements of the above-described preferred embodimentthat are known to those of ordinary skill in the art are expresslyincorporated herein by reference and are intended to be encompassed bythe present claims. Moreover, it is not necessary for a device or methodto address each and every problem sought to be solved by the presentinvention, for it to be encompassed by the present claims. Furthermore,no element, component, or method step in the present disclosure isintended to be dedicated to the public regardless of whether theelement, component, or method step is explicitly recited in the claims.No claim element herein is to be construed under the provisions of 35U.S.C. 112, sixth paragraph, unless the element is expressly recitedusing the phrase “means for.”

1-7. (canceled)
 8. A method for conserving power in a controller for anelectroluminescent display, comprising: providing a plurality of normalmode colors for output on said display; providing a plurality of powersaving mode colors for output on said display, assigning a selectedcolor for each power saving mode color corresponding to one or morenormal mode colors; and switching each normal mode color having anassigned power saving mode color to the assigned power saving modecolor, in response to entering a power saving mode. 9-10. (canceled) 11.A method as recited in claim 8, further comprising indicating thereduction in energy consumed by the display when switched to the powersaving mode colors.
 12. A method as recited in claim 8, wherein theplurality of normal mode colors and the plurality of power saving modecolors are described according to intensity values for each of multiplecolor components.
 13. A method as recited in claim 8, wherein theplurality of normal mode colors and the plurality of power saving modecolors are described according to hue, saturation and luminancecomponents.
 14. In an electroluminescent display controller, theimprovement comprising: providing a plurality of normal mode colors forcontroller output to a display; and providing a plurality of powersaving mode colors for controller output to the display; assigning aselected color to each of said power saving mode colors corresponding toone or more of said normal mode colors toward saving display power whenoutputting said power saving mode colors instead of said normal modecolors; and switching, by said controller, between a normal display modein which the normal mode colors are displayed, and a power savingdisplay mode in which the corresponding power saving mode colors aredisplayed in place of the normal mode colors. 15-17. (canceled)
 18. Animproved electroluminescent display as recited in claim 14, furthercomprising a power saving indicator configured for showing the reductionin energy consumed by the display when switched to the power saving modecolors from the normal mode colors.
 19. An improved electroluminescentdisplay as recited in claim 14, wherein the power saving display mode isentered manually.
 20. An improved electroluminescent display as recitedin claim 14, wherein the power saving display mode is enteredautomatically.
 21. An improved electroluminescent display controller asrecited in claim 14, wherein the display comprises an organicelectroluminescent display.